In recent years, touch panels have been widely used so as to realize small-sized information processing devices enabling intuitive operations and including no device that requires a physically large area, such as a keyboard. As technologies for inputting characters by using such a touch panel, a technology for inputting characters in handwriting on a touch panel (e.g., Patent Literature 1) and a technology for inputting characters by using a virtual keyboard displayed on a touch panel (hereinafter, referred to as a “virtual keyboard”) (e.g., Patent Literature 2) are known.